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Emissions vs. 35"s

XJTodd

XJTodd

NAXJA Forum User
Location
Lafayette, CO
So I showed to to get my emissions doen at the AirCare place in Broomfiled on Friday, and they said "Sorry, tires are too big...we can only go as high as 33s". This is my first time owning a vehicle with 35s and was suprised that they couldn't do it.

I guess my question is, has enyone run in to this before? How did you get around it?

I guess I could always do a quick swap on the rears to something smaller in the parking lot, then swap back after. Only problem is, I don't have any other wheels/tires. If it comes to that, does anyone out there have a pair or 33s I could borrow or trade for a case 'o beer or something?
 
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Stang5lgt said:
I have some 31s you can borrow. Let me know they are mounted and balanced so you drive there and back on them.
Click to expand...

Oh, that would be awesome...I'd probably just drive there and do the quick swap in the parking lot.

I've got a couple coworkers that have Dakotas...was thinking of using their spare tires for this, will these fit my bolt pattern?
 
91 Jeep Project said:
Depends on how they emission. If all they do is the sniffer, then you can have 52s on there. But CO sticks em on the dyno.
Click to expand...
In California they do the dyno as well, and they didnt seem to mind my 35s. How does the size of the tire matter for smogging?
 
To the orig. poster:

What gearing do you have? You need to be careful going too small with the tires and handing your rig over to the goobers running the dyno. The dyno asks them to operate the vehicle at certain speeds..... if you're speedo is set for 35's then they're gonna really work your XJ hard. And, it could mean an emissions failure because of excess NOx created by the higher combustion temps.

If you have stock gears, then the 31's will probably be fine, but I'd shy away from them if you're running 4:56's and especially 4:88's. Find some 33's.


The reason they can't use larger than 33" tires is that the "dyno" is a double roller set up that cradles the drive tires between the rollers. To ensure the vehicle doesn't creep side to side, there's lateral roller bars that are positioned along the sidewalls. Too tall of a tire - especially with aggressive side lugs can cause the tires to climb over the lateral roller bars..... bad thing.
 
YELLAHEEP said:
To the orig. poster:

What gearing do you have? You need to be careful going too small with the tires and handing your rig over to the goobers running the dyno. The dyno asks them to operate the vehicle at certain speeds..... if you're speedo is set for 35's then they're gonna really work your XJ hard. And, it could mean an emissions failure because of excess NOx created by the higher combustion temps.

If you have stock gears, then the 31's will probably be fine, but I'd shy away from them if you're running 4:56's and especially 4:88's. Find some 33's.


The reason they can't use larger than 33" tires is that the "dyno" is a double roller set up that cradles the drive tires between the rollers. To ensure the vehicle doesn't creep side to side, there's lateral roller bars that are positioned along the sidewalls. Too tall of a tire - especially with aggressive side lugs can cause the tires to climb over the lateral roller bars..... bad thing.
Click to expand...
He has stock gears I talked to him already.
 
I have some 32" tires you could borrow, they are in a storage unit that is about 2 blocks from the Northglenn Station. If you can wait until monday we could swap the right there at my storage.
 
YELLAHEEP said:
To the orig. poster:

What gearing do you have? You need to be careful going too small with the tires and handing your rig over to the goobers running the dyno. The dyno asks them to operate the vehicle at certain speeds..... if you're speedo is set for 35's then they're gonna really work your XJ hard. And, it could mean an emissions failure because of excess NOx created by the higher combustion temps.

If you have stock gears, then the 31's will probably be fine, but I'd shy away from them if you're running 4:56's and especially 4:88's. Find some 33's.
Click to expand...
I DO have 4.56 gears and the speedo has been corrected accordingly. ( Stang, I prolly said I didn't have lockers, not the gears ;) )

So you think 33s will be good enough? How about the 32s that DutchVDub has so graciously offered?

:smsoap:...and here come the bitchin'... :smsoap:
Man, sounds like I'm in a tough spot here. I can't believe that they don't accomodate larger size tires. I could imagine it being a problem if say, these tires were illegal or something, or at least some sort of legitimate reason.

I'm already miffed because I've only had this rig for less than 2 months. The guy I had bought it from had just gotten done less than a month before I took delivery. When I went to get my plates, they told me I needed to get it done again in my name. Why is this? Are they doing the emission on the vehicle or me? Ah well, what can you do but just abide... 'Go along and we'll get along' I guess?

Sorry, had to get that out! :)
 
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foodeewaa said:
I DO have 4.56 gears and the speedo has been corrected accordingly.

So you think 33s will be good enough? How about the 32s that DutchVDub has so graciously offered?

...and here come the bitchin'...
Man, sounds like I'm in a tough spot here. I can't believe that they don't accomodate larger size tires. I could imagine it being a problem if say, these tires were illegal or something, or at least some sort of legitimate reason.

I'm already miffed because I've only had this rig for less than 2 months. The guy I had bought it from had just gotten done less than a month before I took delivery. When I went to get my plates, they told me I needed to get it done again in my name. Why is this? Are they doing the emission on the vehicle or me? Ah well, what can you do but just abide... 'Go along and we'll get along' I guess?
Click to expand...
That is right I thought you told me it was stock gears but it was that it didn't have lockers. http://4lo.com/calc/geartable.htm
Here is gearing chart 31s or 32s should work.
 
philip_g said:
register the car in another county w/o emissions.
problem solved :D
Click to expand...
That is a good plan. Tired of nazi gov trying squeeze more money out of the tax payers. They tax our gas, when buy the XJ, next buyer has to pay taxes again, tax repairs, parts, tires, plus excess tax for larger tires, registeration tax, veh property tax, emissions test tax, and they don't even give ya anything for the hose job other then more laws and taxes. Can't wait until Ritter raises reg tax 100 bucks like he wants to. :gee:
 
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